Combined positron emission tomography and computed tomography for the detection of recurrent ovarian mucinous adenocarcinoma

BACKGROUND

The role of combined positron emission tomography and computed tomography (PET-CT) in the diagnosis of recurrent ovarian mucinous adenocarcinoma is uncertain because of previous reports that PET has limited sensitivity in the detection of mucinous neoplasms.

CASE

A 71-year-old white woman presented with complaints of right lower quadrant pain and a palpable adnexal mass. Physical examination and transvaginal ultrasonography revealed a 12 x 13 cm cystic mass in the left side of the pelvis. Exploratory laparotomy, optimal tumor-reductive surgery, total abdominal hysterectomy, bilateral salpingo-oophorectomy, appendectomy, and omentectomy were performed. The diagnosis was FIGO stage IIIC well-differentiated ovarian mucinous adenocarcinoma. The patient was treated with 6 cycles of carboplatin and paclitaxel. Four months after completing chemotherapy, the patient was noted to have an elevated serum CA125 level (72 U/mL), being otherwise asymptomatic. Findings on abdominal and pelvic CT were compatible with postsurgical changes. PET-CT was performed and revealed increased metabolism along the posterior aspect of the right rectus abdominis muscle and abutting the anterior wall of an adjacent loop of bowel.

CONCLUSION

PET-CT may identify clinically occult recurrent ovarian mucinous adenocarcinoma.

Results of the American College of Surgeons Oncology Group Z0050 trial: the utility of positron emission tomography in staging potentially operable non-small cell lung cancer

OBJECTIVES

The American College of Surgeons Oncology Group undertook a trial to ascertain whether positron emission tomography with 18F-fluorodeoxyglucose could detect lesions that would preclude pulmonary resection in a group of patients with documented or suspected non-small cell lung cancer found to be surgical candidates by routine staging procedures.

METHODS

A total of 303 eligible patients registered from 22 institutions underwent positron emission tomography after routine staging (computed tomography of chest and upper abdomen, bone scintigraphy, and brain imaging) had deemed their tumors resectable. Positive findings required confirmatory procedures.

RESULTS

Positron emission tomography was significantly better than computed tomography for the detection of N1 and N2/N3 disease (42% vs 13%, P =.0177, and 58% vs 32%, P =.0041, respectively). The negative predictive value of positron emission tomography for mediastinal node disease was 87%. Unsuspected metastatic disease or second primary malignancy was identified in 18 of 287 patients (6.3%). Distant metastatic disease indicated in 19 of 287 patients (6.6%) was subsequently shown to be benign. By correctly identifying advanced disease (stages IIIA, IIIB, and IV) or benign lesions, positron emission tomography potentially avoided unnecessary thoracotomy in 1 of 5 patients.

CONCLUSIONS

In patients with suspected or proven non-small cell lung cancer considered resectable by standard staging procedures, positron emission tomography can prevent nontherapeutic thoracotomy in a significant number of cases. Use of positron emission tomography for mediastinal staging should not be relied on as a sole staging modality, and positive findings should be confirmed by mediastinoscopy. Metastatic disease, especially a single site, identified by positron emission tomography requires further confirmatory evaluation.